Insulated container

The present invention provides an insulated container that is especially useful in cooling and transporting thermally sensitive materials such as pharmaceuticals, organs, tissues and vaccines. In general, the present invention comprises a container having a base unit and a lid. The container is insulated, preferably through the use of vacuum insulation paneling.A tray holding specimens is placed within the insulated container along with a coolant. To affect the rate at which the coolant draws heat from the specimen within the tray, another competing heat source is placed within the container along with the specimen and coolant. In the preferred embodiment, the competing heat source comprises expanded polystyrene panels coating the inner surface of the insulated container.